A dynamical understanding of stratospheric influences on tropospherica climate and the ocean

Changes in the stratospheric circulation have the potential to affect weather and climate in the troposphere, especially over the high latitudes. In order to better understand such influences, we analyze the relationships among stratospheric, tropospheric, and oceanic variability. We reach our goal...

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Main Author: Kim, Junsu
Format: Text
Language:English
Published: University of Utah 2014
Subjects:
Online Access:https://dx.doi.org/10.26053/0h-0h11-fw00
https://collections.lib.utah.edu/ark:/87278/s6qz5k4d
id ftdatacite:10.26053/0h-0h11-fw00
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spelling ftdatacite:10.26053/0h-0h11-fw00 2023-05-15T13:38:16+02:00 A dynamical understanding of stratospheric influences on tropospherica climate and the ocean Kim, Junsu 2014 application/pdf https://dx.doi.org/10.26053/0h-0h11-fw00 https://collections.lib.utah.edu/ark:/87278/s6qz5k4d en eng University of Utah Climate Ocean circulation Ozone Stratosphere Time scale Troposphere article-journal Text ScholarlyArticle 2014 ftdatacite https://doi.org/10.26053/0h-0h11-fw00 2021-11-05T12:55:41Z Changes in the stratospheric circulation have the potential to affect weather and climate in the troposphere, especially over the high latitudes. In order to better understand such influences, we analyze the relationships among stratospheric, tropospheric, and oceanic variability. We reach our goal with the aid of coupled chemistry-climate models and coupled atmosphere-ocean models. Over the past decades, ozone depletion in the Antarctic stratosphere has been accelerating the poleward side of the stratospheric polar vortex. We suspect that the change in the winds in turn affects the concentrations of ozone. This idea is investigated with coupled chemistry-climate models. We find a strong indication for the existence of a positive feedback between ozone depletion and change in the circulation: the chemical ozone loss feeds back into the stratospheric circulation, and changes in the circulation produce more ozone deficit. Climate models tend to systematically overestimate the persistence time scale of extratropical variability, in particular over the Southern Hemisphere. The systematic overestimation in climate models raises the concern that the models are overly sensitive to external forcings and that future projections based on those models are unreliable. We investigate issues concerning the persistence time scale of the annular mode using reanalysis and model data. We find that the 50-year record of historical observations is probably too short to derive a stable estimate of the annular mode time scale that may be used to evaluate climate models. We also find a robust relationship between the magnitude and the seasonal timing of the time scale in both stratosphere and troposphere, confirming and extending earlier results of a dynamical coupling between the stratosphere and the troposphere and of influences of stratospheric variability on the troposphere. Extreme events in the stratosphere are known to alter tropospheric weather and climate. However, it is still unclear whether the stratosphere also has the capacity to affect the ocean and its circulation. This possibility is suggested from observations which show low-frequency covariability between the stratosphere and the Atlantic thermohaline circulation. We use simulations from coupled atmosphere-ocean models to explore more systematically a possible stratospheric influence on the oceanic circulation over the North Atlantic Ocean on multidecadal time scales. Our analysis identifies the stratosphere as a previously unknown source for decadal climate variability in the troposphere and suggests that the stratosphere forms an important component of climate that should be well represented in models. Text Antarc* Antarctic North Atlantic DataCite Metadata Store (German National Library of Science and Technology) Antarctic The Antarctic
institution Open Polar
collection DataCite Metadata Store (German National Library of Science and Technology)
op_collection_id ftdatacite
language English
topic Climate
Ocean circulation
Ozone
Stratosphere
Time scale
Troposphere
spellingShingle Climate
Ocean circulation
Ozone
Stratosphere
Time scale
Troposphere
Kim, Junsu
A dynamical understanding of stratospheric influences on tropospherica climate and the ocean
topic_facet Climate
Ocean circulation
Ozone
Stratosphere
Time scale
Troposphere
description Changes in the stratospheric circulation have the potential to affect weather and climate in the troposphere, especially over the high latitudes. In order to better understand such influences, we analyze the relationships among stratospheric, tropospheric, and oceanic variability. We reach our goal with the aid of coupled chemistry-climate models and coupled atmosphere-ocean models. Over the past decades, ozone depletion in the Antarctic stratosphere has been accelerating the poleward side of the stratospheric polar vortex. We suspect that the change in the winds in turn affects the concentrations of ozone. This idea is investigated with coupled chemistry-climate models. We find a strong indication for the existence of a positive feedback between ozone depletion and change in the circulation: the chemical ozone loss feeds back into the stratospheric circulation, and changes in the circulation produce more ozone deficit. Climate models tend to systematically overestimate the persistence time scale of extratropical variability, in particular over the Southern Hemisphere. The systematic overestimation in climate models raises the concern that the models are overly sensitive to external forcings and that future projections based on those models are unreliable. We investigate issues concerning the persistence time scale of the annular mode using reanalysis and model data. We find that the 50-year record of historical observations is probably too short to derive a stable estimate of the annular mode time scale that may be used to evaluate climate models. We also find a robust relationship between the magnitude and the seasonal timing of the time scale in both stratosphere and troposphere, confirming and extending earlier results of a dynamical coupling between the stratosphere and the troposphere and of influences of stratospheric variability on the troposphere. Extreme events in the stratosphere are known to alter tropospheric weather and climate. However, it is still unclear whether the stratosphere also has the capacity to affect the ocean and its circulation. This possibility is suggested from observations which show low-frequency covariability between the stratosphere and the Atlantic thermohaline circulation. We use simulations from coupled atmosphere-ocean models to explore more systematically a possible stratospheric influence on the oceanic circulation over the North Atlantic Ocean on multidecadal time scales. Our analysis identifies the stratosphere as a previously unknown source for decadal climate variability in the troposphere and suggests that the stratosphere forms an important component of climate that should be well represented in models.
format Text
author Kim, Junsu
author_facet Kim, Junsu
author_sort Kim, Junsu
title A dynamical understanding of stratospheric influences on tropospherica climate and the ocean
title_short A dynamical understanding of stratospheric influences on tropospherica climate and the ocean
title_full A dynamical understanding of stratospheric influences on tropospherica climate and the ocean
title_fullStr A dynamical understanding of stratospheric influences on tropospherica climate and the ocean
title_full_unstemmed A dynamical understanding of stratospheric influences on tropospherica climate and the ocean
title_sort dynamical understanding of stratospheric influences on tropospherica climate and the ocean
publisher University of Utah
publishDate 2014
url https://dx.doi.org/10.26053/0h-0h11-fw00
https://collections.lib.utah.edu/ark:/87278/s6qz5k4d
geographic Antarctic
The Antarctic
geographic_facet Antarctic
The Antarctic
genre Antarc*
Antarctic
North Atlantic
genre_facet Antarc*
Antarctic
North Atlantic
op_doi https://doi.org/10.26053/0h-0h11-fw00
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